[PATCH v12 60/84] KVM: PPC: Use __kvm_faultin_pfn() to handle page faults on Book3s Radix
From: Sean Christopherson <seanjc@google.com>
Date: 2024-07-26 23:54:43
Also in:
kvm, kvm-riscv, kvmarm, linux-arm-kernel, linux-riscv, linuxppc-dev, lkml, loongarch
Subsystem:
kernel virtual machine for powerpc (kvm/powerpc), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Replace Book3s Radix's homebrewed (read: copy+pasted) fault-in logic with __kvm_faultin_pfn(), which functionally does pretty much the exact same thing. Note, when the code was written, KVM indeed didn't do fast GUP without "!atomic && !async", but that has long since changed (KVM tries fast GUP for all writable mappings). Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/powerpc/kvm/book3s_64_mmu_radix.c | 29 +++++--------------------- 1 file changed, 5 insertions(+), 24 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index 8304b6f8fe45..14891d0a3b73 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c@@ -829,40 +829,21 @@ int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu, unsigned long mmu_seq; unsigned long hva, gfn = gpa >> PAGE_SHIFT; bool upgrade_write = false; - bool *upgrade_p = &upgrade_write; pte_t pte, *ptep; unsigned int shift, level; int ret; bool large_enable; + kvm_pfn_t pfn; /* used to check for invalidations in progress */ mmu_seq = kvm->mmu_invalidate_seq; smp_rmb(); - /* - * Do a fast check first, since __gfn_to_pfn_memslot doesn't - * do it with !atomic && !async, which is how we call it. - * We always ask for write permission since the common case - * is that the page is writable. - */ hva = gfn_to_hva_memslot(memslot, gfn); - if (!kvm_ro && get_user_page_fast_only(hva, FOLL_WRITE, &page)) { - upgrade_write = true; - } else { - unsigned long pfn; - - /* Call KVM generic code to do the slow-path check */ - pfn = __gfn_to_pfn_memslot(memslot, gfn, false, NULL, - writing, upgrade_p); - if (is_error_noslot_pfn(pfn)) - return -EFAULT; - page = NULL; - if (pfn_valid(pfn)) { - page = pfn_to_page(pfn); - if (PageReserved(page)) - page = NULL; - } - } + pfn = __kvm_faultin_pfn(memslot, gfn, writing ? FOLL_WRITE : 0, + &upgrade_write, &page); + if (is_error_noslot_pfn(pfn)) + return -EFAULT; /* * Read the PTE from the process' radix tree and use that
--
2.46.0.rc1.232.g9752f9e123-goog